Serum samples were collected in the 1960's in the Upper Volta region of Africa, presently known as Burkina Faso, for a measles vaccine study. These studies were conducted by Dr. Harry Meyer, Dr. Daniel Hostetler, and Barbara Bernheim. Originally these sera were taken from children aged 3-30 months who were participants in a measles vaccine study. Approximately 600 sera were stored at CBER for the past 30+ years and recently were tested for the presence of HIV-2 and possibly HIV-1 antibodies. HIV-2 is present in Western Africa and has been dated as far back as 1966. These sera were screened in a Genetic Systems combination HIV-1/HIV-2 ELISA, first in single wells and then the positives were retested in duplicate. Samples which were reactive in duplicate were subsequently tested in separate Genetic Systems HIV-1 and HIV-2 ELISA kits. Preliminary results showed that about 4% of the total sample set were positive for HIV-2 and about 6% were positive for HIV-1. The ELISA positive samples were then tested in Cambridge Biotech Western Blot kits for confirmation. All 24 samples run on the HIV-2 Western Blot showed the samples to be indeterminate. All were positive for p26 and other bands but did not have a second required band to be positive. Of the 33 samples tested for HIV-1 Western Blot, 31 were indeterminate with most having only the p24 and other non-specific bands. Two samples appeared to be positive and are currently being retested. If they prove to be positive upon retesting, further evaluation will be done. All of the sera that were run on western blots are also presently being tested by PCR to see if RNA specific viral sequences can be detected.